JP2000213900A - Blasting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain sufficient explosion effect and to reduce blasting energy being transferred to the surrounding by punching a required number of explosion holes from the peripheral surface of an object to be broken at the outer periphery of a core hole and loading explosive into the explosion hole for exploding. SOLUTION: A core hole 2 is excavated at an exploded part 1, and a sufficient free surface 1 for improving the efficiency of blasting is composed by the inner-periphery surface of the core hole 2 and that of a remaining outer- periphery part 12. Also, at the outer-periphery part 12, a required number of explosion holes 3 are punched from the peripheral surface, and required explosive is loaded into the excavated explosion holes 3. Explosives such as dynamite being used for the publicly known blasting method are used. Also, since the exploded part 1 has a sufficient free surface 11, sufficient blasting can be made with much less amount also for the amount of explosives to be used as compared with a method for blasting an entire section by blasting, thus reducing blasting energy to be transferred to a peripheral part and fully clearing an allowable vibration value to surrounding houses and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blasting method for crushing an object to be crushed.

[0002]

2. Description of the Related Art Explosives such as dynamite are used for crushing soft and hard members such as construction of shafts (foundations) and shafts (tunnels), quarries, demolition of concrete blocks, and destruction of large rocks. Crushing has been carried out by blasting. When crushing by blasting, in order to increase the blasting efficiency, it is necessary to secure a wide free surface, which is the blasting location of the crushed material to be blasted. Therefore, in order to ensure a wide free surface for blasting, for example, in deep excavation, a V-shaped blast hole is drilled in the center of the pile as a control blast, and explosives are loaded into the blast hole and By doing so, the heart is removed. A wide free surface is secured by such controlled blasting, and crushing by blasting is performed.

[0003]

The control blast described above has the following problems.

<A> Controlled blasting of a crushed object to be subjected to centering has a narrow free surface for blasting, so that the blasting efficiency is low. <B> From this, the amount of explosive used for decentering is about twice the amount of explosive for crushing the outer periphery of the crushed material left after decentering, which is uneconomical and the amount of explosive to handle The danger of the worker increases with the increase in the number of workers. <C> In the case of the blasting method, it may be necessary to perform the blasting in consideration of the effect of blasting energy (vibration or the like) transmitted to the surroundings. Specifically, as described above, when the amount of explosive used for centering is large, blast vibration becomes a problem.
Specifically, the allowable vibration value is determined by the distance from the blasting point to the house, and blasting using an explosive amount exceeding this allowable value cannot be performed. <D> If the amount of gunpowder is regulated by the expected allowable vibration value and the centering cannot be performed by a single blast, reduce the amount of gunpowder to the amount that clears the allowable vibration value, increase the number of blasting times, and perform centering. However, this method was not economical, and the explosion frequency increased, the workers took longer to handle explosives, and the workers required more dangerous work, so they were not used only in special cases. .

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and provides a sufficient blasting effect with a small amount of explosive, and reduces blasting energy transmitted to the surroundings. The purpose is to provide a blasting method.

[0006]

As a means for solving the above-mentioned problems, the present invention is to load explosives into a blast hole drilled on a free surface of a blasting portion of an object to be crushed, and to use the explosive power of the explosives. In the blasting method of crushing an object to be crushed, a core hole is excavated in advance at a blasting point, and the inner peripheral surface of the core hole and the peripheral surface of the remaining crushed object constitute a free surface, and the core hole Drill the required number of blast holes from the peripheral surface of the crushed material left on the outer circumference,
By loading explosives into the blast hole and blasting,
A blasting method characterized by crushing an object to be crushed.

[0007]

First Embodiment A blasting method according to the present invention will be described below with reference to the drawings, taking a shaft as an example.

<B> Core hole excavation process (FIGS. 1 and 2) First, in order to increase the blasting efficiency of the blasting point 1 of the crushed material,
A wide free surface 11 of the blasting part 1 is secured. In particular,
A core hole 2 having a non-circular cross section is excavated at a central portion of the blasting portion 1 by a known mechanical excavation. As a device for excavating the core hole 2, for example, an excavator disclosed in Japanese Patent Application Laid-Open No. H8-100584 or an excavator disclosed in Japanese Patent Application Laid-Open No. 8-291681 can be used. According to these excavators and excavators, the core hole 2 having a non-circular cross section can be easily excavated. The non-circular cross-section, which is the cross-sectional shape of the core hole 2 described above, preferably refers to a rectangular cross-section such as a polygon, but has a side with a large curvature such as an elliptical cross-section that has a substantially linear shape. It may be shaped. As described above, the core hole 2
The free surface 11 is constituted by the inner peripheral surface of the core hole 2 and the peripheral surface of the remaining outer peripheral portion 12 without performing control blasting by excavating by mechanical digging or the like. As a result, a free surface 11 sufficient to enhance the blasting efficiency is formed at the blasting point 1.

<B> Step of Blasting Outer Peripheral Portion of Core Hole Next, a step of excavating the outer peripheral portion 12 of the core hole 2 by blasting will be described.

<B-1> Drilling of blast hole (FIG. 3) The outer peripheral portion 12 of the blasting point 1 located on the outer periphery of the core hole 2
Crush by blasting. Therefore, the required number of blast holes 3 are formed in the outer peripheral portion 12 from the peripheral surface. The blasting point 1 has a free surface 11 necessary for blasting by excavating the core hole 2 in advance, so that the number of blast holes is reduced as compared with the conventional method of crushing all sections by blasting. Sufficient crushing can be performed even if it is performed.

<B-2> Loading of explosives The necessary explosives are loaded into the blast holes 3 drilled in the above-described process. As explosives, explosives such as dynamite used in known blasting methods are used. As described above, since the blasting portion 1 has a sufficient free surface 11, compared to the conventional method of crushing the entire cross section by blasting, the amount of explosives to be used can be sufficiently crushed with a smaller amount in each step. It is possible to do. Accordingly, it is possible to reduce the blast energy transmitted to the peripheral portion, and it is possible to sufficiently clear the permissible vibration value to a nearby house or the like.

<B-3> Crushing of outer peripheral portion (FIG. 4) By explosives charged in the blast holes 3 in a predetermined order (for example, in the numerical order shown in FIG. 4), The outer peripheral portion 12 of the core hole 2 can be crushed. This makes it possible to crush and excavate the blasting portion 1 to a predetermined depth.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 5, a drilling pattern of a blast hole at the time of controlled blasting and a drilling pattern of a core hole excavated in a non-circular cross section according to the present invention are shown as examples of a deep foundation work. Compare. When the diameter of the deep foundation is 3.5 m, 30 blast holes 3a of the blasting point 1a by the conventional control blasting shown in FIG. 5 are required. On the other hand, in the case of the present invention in which the core hole 2 is excavated in advance as shown in FIG. 1, the number of blast holes 3 can be reduced to 24. Further, the amount of explosives (dynamite) required for control blasting is 6.4k because the free surface 11a is flat and the area is small.
Although g is required, according to the present invention, the area of the free surface 11 can be increased by forming the core hole 2, so that the area can be reduced to 4.2 kg.

[0014]

Second Embodiment In the first embodiment of the present invention, blasting for a crushed portion of the same quality has been described.
Subsequently, a case in which a crushed portion having a plurality of soft and hard properties is blasted will be described. In this case, it is possible to perform a well-known mechanical excavation for the soft part, but for the hard part, a core hole is excavated in the center part, and a blast hole is drilled in the outer peripheral part of the core hole to blast. I do. At this time, if the soft portion is excavated in advance, the free surface can be further expanded, and a sufficient blasting effect can be achieved with a smaller amount of explosive.

[0015]

Third Embodiment In the first and second embodiments of the present invention, an example is described in which a core hole is excavated in advance at the center of a blasting part in order to secure a wide free surface of the blasting part. The present invention is not limited to this, and it is possible to obtain a necessary free surface by forming a plurality of core holes at necessary positions, as well as forming the core holes at necessary positions on the free surface.

[0016]

Fourth Embodiment In each of the above-described embodiments of the present invention, since a sufficient free surface is formed in the centering work by blasting, in addition to crushing by blasting using explosives, a hydraulic wedge type Even if crushing by a non-blasting method using a known crushing method such as using a rock crusher, using a rubber tube type crushing device, or using a static crushing agent such as intumescent cement, high effects can be exhibited. It is.

[0017]

<B> Since the centering is performed prior to the blasting by mechanical digging or the like, the blasting portion of the crushed material can have a wide free surface for blasting, and the blasting efficiency can be increased. <B> From this, the amount of explosive used for blasting can be significantly reduced compared to the amount of explosive used for conventional blasting, and it is very economical. Safety can be improved. <C> Further, the problem of blast energy (vibration and the like) transmitted to the surroundings can be solved with the decrease in the amount of explosive. In other words, depending on the distance from the blast location to the house,
Even at a site where an allowable vibration value is determined, sufficient blasting can be performed within this allowable value. <D> Since blasting can be performed within the limit of the amount of explosives due to the allowable vibration value, there is no need to perform multiple blasting with reduced explosives as in the past, and the danger for workers involved in blasting work is greatly reduced. Becomes possible.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a blasting method according to the present invention.

FIG. 2 is an explanatory view of a core hole constituting a free surface.

FIG. 3 is an explanatory view of a blast hole

FIG. 4 is an explanatory view after crushing by blasting.

FIG. 5 is an explanatory diagram of a conventional blasting method involving control blasting.

Claims (4)

[Claims] Claims: 1. A blasting method in which explosives are loaded into a blast hole drilled on a free surface of a blasting point of an object to be crushed and the explosive force of the explosives crushes the object to be crushed. Excavating, forming a free surface with the inner peripheral surface of the core hole and the peripheral surface of the remaining crushed object, and forming a required number of blast holes from the peripheral surface of the crushed object left on the outer periphery of the core hole. Drilling, loading explosives into the blast hole and blasting it,
A blasting method characterized by crushing an object to be crushed. 2. The blasting method according to claim 1, wherein
A blasting method, wherein the core hole is formed at a central portion of the blasting point. 3. The blasting method according to claim 1, wherein
A blasting method, wherein the core hole has a non-circular cross section. 4. The blasting method according to claim 2,
A blasting method, wherein the non-circular cross-sectional shape of the core hole has a straight portion.